Developing mechanism for microfilm

ABSTRACT

The disclosure of the invention is directed to an improvement in the developing mechanism for duplicating sheets of heat sensitive latent image bearing microfilm. The microfilm sheets are copied by exposing film from a roll through a master microfilm sheet, cutting the exposed film from the roll and developing the film in a heating chamber. The heating chamber contains thermostatically controlled heating elements to maintain the temperature at substantially 285*-290* Fahrenheit for a dwell time of 5 - 7 seconds. The film is continuously moved through the heating chamber by a roller conveyor providing a continuously moving and changing contact area with the film on an emulsionless surface. The film is transferred to a belt conveyor having end rollers no larger in diameter than the rollers in the roller conveyor but having a flat surface to provide cooling for the developed sheets before being delivered to a collection point in the mechanism.

Smith et a];

[56] References Cited-v [54] DEVELOPING MECHANISM FOR MICROFILM [75]Inventors: Alan Smith/New Brighton, Irwin Y L. Irwin, Coon Rapids, bothof Minn.

[73] Assignee: Calight,Inc.,Minneapolis h'linn [22] Filed: June 23, 1972[21] App]. No.: 265,556

[52] US. Cl 95/8 9 R, 95/89 A, 219/216,

. 219/388, 355/100, 355/106 51 "161. CI. ..G03d 3/00 [58] FieldofSearch....- ..95/89 11, 9 11,14;

SSS/100,103,106,-107, 27, 28; 219/216,

v UNITED STATES'PATENTS v 3,557,675 1 1971 86116161.. 355/27 x 3,282,18311 1966 T111116 e161. 95 14x 3,449,547 6 1969 06661 1666161. ...'219'388x 3,458,314 7 1969 1.111661112166161... 95/89RX Doyle 219/469 1451Nov, 27, 1973 Primary Examiner-Richard L. Moses Attorney-Everett J.Schroeder et al. I

[57] ABSTRACT The disclosure of the invention is directed man im- 1provement in the developing mechanism for duplicating sheets of heatsensitive latent image bearing microfilm. The microfilm sheets arecopied by exposing film from a roll through a master microfilm sheet,cutting the exposed film from the roll and developing the film 4 in aheating chamber. The heating chamber contains thermostaticallycontrolled heating elements to maintain the temperature at substantially285290 Fahrenheit for a dwell time 6'15 7 seconds. Thefilm iscontinuously moved through the heating chamber by a roller conveyorproviding a continuously moving and changing contact area with the filmon an-emulsionless surface. The film is transferred to'a belt conveyorhaving end rollers no larger in diameter than the rollers in I theroller conveyor but having a flat surface to provide cooling.for thedeveloped sheets before being delivvfirecl'to a collection point in themechanism.

12 Claims, 3 Drawing Figures V l n :DEVELOPING MECHANISM FOR MICROFILM.This invention is directed to a microfilm duplicating mechanism andmoreparticularly to the means for developing the exposed microfilm whichisheat sensitive and includes a latent image.

' In the duplication process of duplicating microfilm which hasa heatsensitive latent image it has been found that some of these filmsrequire a developing time of approximately Sto 7'secondsin a heatingchamber forming the developer which renders the plastic ma te rialforming the film substrate to become very soft andpliable'preventing anyform of pressure con- By reference to the Figures, and particularly FIG.1 where a roll of film 10 is suspended upon a spindle 11, it is drawnbetween an alignment spool12to pass over a film holder 13. Filmholder-l3 carries a masterfilm' 14 which is tobe copied A .cover plate15 is hingedly supported at its rear throughsuitable means so that itmay be drawn down tightly upon holder member l3 tact with theemulsionside of the film. Some films are made with a rapid developing time sothat heatmay be applied to the film and the filmvpassed through pinchrollers to conduct the film through the developer without having theemulsion separate from the film suband thus hold film 10 in contact withthe master 14. A mask 16 below film holder 13 works in conjunction witha shutter mechanism 17 which hasan elongated slot' 20 formed in thecenter of a'half section of a cylindrical member which has a lamp 21 inthe form of an ultraviolet light that causes its rays to be emittedupwardly through the master film to be copied to expose film 10. Shuttermember 17 rotates through 180 to -block the light. from beingtransmitted-through mask 16 permitting light to pass through slot 20 andagain strate. However, for the film first described above, any

attempt to pass the film continuously through pinch rollers causes theemulsion to be transferred to the pinch rollers and thus ruin the newfilm sheet.

Because the film does become 'very pliable, it is necessary to move thefilm in sucha manner that there is little contact with the conveyingmechanism'in. orderto prevent hot or burned spots on the film such asmaybe encountered where a flat belt type conveyor may be used toconvey'the film through theheat chamber. It is also necessary'toremovethe-film from the developer and cause it to cool'on a-flatsurface sothat the film sheet remains flat-and' do'es' not incur a P I aflent set?to the film from any sag which may be .imparted through the use of acontinuously-'' moving contact member with the film.

, It is therefore a general objec'tof this invention to provide animproved developer of heat sensitive latent image bearing microfilm.

It is'still a further object of this invention to provide adeveloper ofheat sensitive latent image bearing microfilm in which the exposed filmis moved through the developer having continuously moving and a changingcontact'areas engaging the film. f t It is still a further object ofthis invention to provide means for moving film through a developer byengaging the emulsionless surfaces of the film 'to be cured by heat. 1

It is yet another object of this invention to provide a roller conveyormeans to transport the heat sensitive latent image bearing microfilmthrough the developer. Itis still another object of this invention toprovide means for'developing heat sensitive latent imageb'earing'microfilm at a temperature range of 285290,"

'veloper with a dwell time of 5 j- 7 seconds.

These and other objects and; advantages of the invention will more fullyappear from the following description, made in connection with theaccompanying drawblock the light from passing mask 16. The rate at whichshutter member 17 is oscillated provides'an adjustment for thedeveloping time. The shield 17 is pivoted about an axis 22 which permitsthe 180 movement of the shutter member 17.

After the film has been exposed, the pressure is re leased from cover 15and film 10 is advanced by a pair of rollers 23 and 24'which are drivenby amotor mechanism to causean advancement of film 10 one length of themaster-film 14. The film is then stopped and a knife mechanism 25 isenergized which cuts the film the'p'roper length." Film 10 is thenadvanced through a pair of curved guide members 26and 27 until itreaches anotherpair of rollers 30and 31, one of which is driven I by amotor-and the other which. maybe av pinch roller to further guide-andmovefilm member 10 through an intermediate pair of guide members 32 and33 which causes the film sheet 10 to be moved vertically between guides32 and 33. 1 v v I Another pair of rollers 34 and 35, one of which is apinch roller and the otherof which is driven through a chain driveconnected to the .drivingmotor, causes film 10-to be engaged andpropelled downwardly between another. pair of curved guide members 36and37.

I Guidemernbers 36 and 37 cooperate to change the course ,offilm sheet10 from a verticaldownward movement to one which is substantiallyhorizontal. Film sheet 10 is then engaged by another pair of rollers .40and 41 where roller 40 is in the form of a pinch rol- Fahrenheit whileconveyingthe same through the deings, wherein like referencecharactersrefer to the same or similar parts throughout. the severalviews, and

inwhich: t

FIG. 1 is a diagrammatic view of the invention showing the mechanism forexposing and developing heat sensitive latent image bearing microfilm;

FIG. 2 is an elevational side view of the heat chamber and conveyormechanism from the developermecha nism; and I FIG. 3 is an electricalschematic showing the electrical circuit controlling the duplicatingmechanism.

.-v eyor and conduct film sheet10 across ler and roller 41 is a drivenroller, the driving mecha} nism being a constant speedmotor. A pluralityof rolis rotated, roller 71 being disposed adjacent roller of the rollerconveyor and having a diameter no larger than roller 50to cause aminimum amount of droop" of the film in transferring from the rollerconveyor to the belt conveyor. Another roller 72 rotatably secures thebelt in place at theend of the conveyor and film sheet 10 isthen-retained by acollector box 80 at the end of conveyor.70 A coverplate 81 is formed about I conveyor to direct any of the aircurrentsused generally'to cool lamp 21 from reaching the film sheets 10 therollers on i and disturbingthem during their cooling period in movingfrom the developer to the collector box 80.

For a .more complete disclosure of the exposure mechanism and thatportion of the duplicatingdevice before reaching the developer in theform of the heating chamber 60 and conveyor 70, reference may be had toa co-pending application entitled Microfilm Duplieating Device? andassigned to the same Assignee.

Developer 60 is in the form of a metal enclosure. 65 which has an inletopening 66 and an outlet opening 67 through which'film enters and is.discharged. A' i metal barrier68 is secured between the floor of the box65 and below roller members 41 through 50. Heating elements 61 through64 are contained with a cavity v69 formed between barrier 68 and thesides and bottom of box 65. A thermostat 73 is disposed on the upperoutside portion of heating chamber 60 and is used to control theelectrical connections to heating elements 61 and 62 as shownschematically in FIG. 3.

A drive sprocket 51 is rotatably, secured to case 65" and has sevenidler sprockets 52 53, 54, 55 56, 57, and 58 rotatablysecured to housingin cooperation witha chain 59 which engages sprocket teeth found on eachof rollers 41 through 50. Sprocket 51 is rotated in such a manner as tocause rollers41 through 50 to pro- 1 10 volts 60 cyclesis applied'tolines 90 and 91 through a master switch 92 which applies current througha fuse 93 and energizes a lamp 94 indicating that theequipment is readyto start developing. it will of course be understood that a lamp switch95 will also be closed applying current to ultraviolet lamp 21 which isshown diagrammatically in FIG. 1. After an appropriate warmup period,and with a master 14 in film carrier. 13, a print switch 96 ismomentarily closed which causes a control relay CR2 in line 2 tobeenergized and which in turn closes relay contacts CR2 in line 2 thusforming a holding circuit. Connected in parallel with control relay CR2,is a timed relay TR3 which closes its contacts-up to 1 secondlater,closing eontactsTR3 in line 4. A shutter drive cam. 100 in its at restposition, closes a switch 101 in line 4 thus applying current to timedrelay TR4 which applies a pulse for a fraction of a second to a camsolenoid 102. The duplicating mechanism uses a number of motors, severalof which are connected to the mechanical drive through the means of amechanically engaged clutch. The clutches are spring loaded and have acam or collar control member held duce a movement of film sheet 10 fromopening 66 through opening I 67 in the heating chamber 60. Sprocket 51is connected to a motor 74 through suitable means such as a shaft 75. Itmay also be desirable to paint the inside of cavity 69-so that a moreuniform radiator is formed by barrier 68. Additionally, a conveyor motor76 is connected to driving roller 71 through suitable means such as ashaft 77. Motors 74 and 76 are generally constant speed motors andoperconveyor .70-without appreciable distortion and upon cooling onconveyor 70, the film will remain in'a flat condition.

Plate 81 may be eliminated if cooling currents of air are not admittedto the area in which the film is conveyed on conveyor 70, it beingunderstoodthat the film must lie flat on the conveyor in order toproduce a'flat sheet before reaching the collection point 80 at the endof conveyor 70. I

It has also been found that cavity 69 is heated to the correcttemperature of 285 to 290 Fahrenheit by ap-' plying current to heaters63 and 64 continuously, the heaters being approximately 200 Watts each;The incremental control needed to keep the temperature variation withinthe limits just described is achieved with heaters 61 and 62 which areconnected in series with each other through the use of a thermostat 73,

heaters 61 and 62 being of 50 Watt ratings.

OPERATION The control circuit is shown in FIG. 3 in simplified formshowing the mechanical structure as controlled by the electricalcircuit. To better understand the circuit, the lines appearing between apair of power lines 90 against rotation through a detentactuated by asolenoid. Upon release for'rotation the clutch may rotate the cam 180 or360 depending on the number of detents. A clutch 103 is actuatedbysolenoid 102, and a motor 104 provides a rotational drive for theclutch. Clutch 103 drives a cam 105 to cause cover 15 to be securedagainst film carrier .13 and also drives a cam 106 which is used toactuate aswitch,l07 and cause switch 107: to engage the contact on line10.

Current is also applied to timed relayTRS in line 5, and contacts TRSareclosed applying current through switch 107'to a shutter solenoid 110.A clutch 111 is mechanically connected to solenoid 1 10 and is alsomechanically connectedto a variable speed motor 112 which causes arotation of shutter17and switch cam 100. After cam 100 rotates, thecontacts of switch 101 are broken and the circuit is broken to relaysTR4 and TR5 which opens the circuit to the shutter solenoid 110. Afterthe shutter has contained its 180 movement through an eccentric arm,it-comes to restlwith the light from lamp 20 being blocked from entry tothe film'carrier and'master film14. However, when cam 100 rotates 180,switch 101 is again actuated momentarily which again energizes relaysTR4' and TR5 to film 10and allow it to be drawn through between thecover 15 and holder 13.

Switch 107 now engages its contact in line 9, apply-' ing current to ametering roll solenoid 113. A clutch 114 is engaged by solenoid 113 andmechanically connects a drive motor 115 through an output shaft whichand 91 are labeled at the left, line numbers designating the particularelectrical circuits which will be used to identify the componentstherein. Alternating current of through the guide members. As film 10 isadvanced by motor and metering roll 24, cam 116 permits a switch 117 inline 9 to engage another set of contacts,

connecting it directly to a control relayCR6 in line 6. A holdingcircuit is created in line 6 through a pair of normally open contactsCR6. I

connected with the line, energizing timed relay TR7 through controlrelay contact CR6 in line8. Timed relay TR7 has two forms of delay, oneof which occurs while the relay coils are energized and the other delayfollows de-energization of the coils for a period of time beforereturning the circuit to the condition shown in FIG. 3. Line 7 forms theholding circuit during the on delay and at the endof the off delay,relay TR7 is returned to the condition shown in; the drawing. Uponenergizing timed relay TR7, the normallyclosed contacts'in line '1 areopen, thus breaking the circuit to CR2, TR3, TR4, TRS, and CR6. In otherwords, the

film has been advanced alength of themaster film and the sequence isready to berepeated. Through the use of a cut switch 120, in line 12, asolenoid 121 is actuated which is directly connected to knife 25 tosever I the filmat thatpoint.

. It may be desirable'to adjust the speed of the shutter motor and thismay be accomplished through the use of a mechanism such as the DaytonTriac Control,1No.

I 4x796 which is an'SCR control for use with motor 112 and is designatedas a speed control 122.

As explained briefly before, heat is maintained in the Iheatingchamberthrough the useof heaters 63 and 64 and the heat variation is maintainedand controlled through the use of series heaters 61 and 62 controlled bythermostat 73. I

The developer motor 74 drives the roller conveyor within the developercausing the sheet film to be delivered to conveyor 70 which is driven bymotor 76.-

It will of course be. understood that mechanism-may be operated in anautomatic'mode and that numerous copies may be made by the use of acounter. The disclosure of such a mechanism is found in the co-pendingapplication mentioned previously.

vIt will, of course, be understood that various changes may be made inthe form, details, arrangement and pro-' portions of the withoutdeparting fromthe scope of the invention which consists of the mattershown and described herein and set forth What is claimed is: y 1

1. An improvement in a' duplicating mechanism for heat sensitive latentimage bearingrnicrofilm having a film holder for holding suchmicrofilmto be duplicated I with a film exposure device disposedinoperable position in spaced and confronting relationship therewith,

' said film exposure device cooperating with means for supplying film tobe exposedto the film exposure'device and havinga cutter operablydisposed and controlled to deliver selected lengths of exposed microfilmoutlet openings and having continuously moving and changing contactareas engaginga substantially emulsionless surface of such selectedlengths of microfilm, said transport means operating at a I speedpermitting the latent image in such film to be fully developed; 3

in'the appended claims.

, '6 c. and a conveyor mechanismcomm'unicating with said filmtransporting means and said outlet opening of said heating chamberhaving a flat support thereunder conveying such developed film to acollection point, said conveyor mechanism conveying such film in a flatcondition until the film emulsion is set and the latent image is fixedtherein. I 2. The structure set forth in claiml wherein said heatingchamber includes: i I I a I thermostatic control means connected to lessthan I the total of said plurality of heating elements providingincremental changes in] heat variations within saidheatirrg chamber. I rI 3. The structure set forth in claim 1 wherein said inlet and outletopenings in said heating chamber are sub stantially in horizontalopposition to each other. I

4. The structure set forth in claim 1 wherein said film transportingmeans includes roller conveyor means constructed and arranged to conveysuch selected '5. The structure set forth in claim 4 wherein said con- Iveyor mechanism includes an endless belt conveyor having at least a pairof rollers at each end thereof, the end communicating with said filmtransporting means having a roller no larger in diameter than therollers in said roller conveyor means. I 6. The structure set forth inclaim 1 whereinsaid heating chamber maintains a temperature range be.-tween 285 and 290 Fahrenheit 1. The structure set forth in claim6wherein said film transporting means moves such selected lengths ofmicrofilm through said heating chamber in'substantially I 5 7 seconds.

8. The structure set forth in claim 2- wherein said heatingchamberincludes: Y a cavity containing said plurality of heating elements,

said cavity being disposed beneath said film transporting means. v I 1 i9. The structure set forth in claim 4'wherein said film 40 transportingmeans includes: t

lected lengths" of exposed. microfilm are engaged I being exposed to theheat from said heating cham ber.

' image-bearing microfilm comprising:

fonned therein admitting and discharging respectively selected lengthsof exposed and developed microfilm, said chamber including a'pluralityof heating elements disposed generally opposite the emulsionsurface ofvsuch selected lengths of ex-' posed microfilm;

. film transporting means constructed and arranged within said heatingchamber between said inlet and I outlet openings and having continuouslymoving I and changing contact areas engaging a substantiallyemulsionless surface of such selected lengths of microfilm, saidtransporting means operating at a speed permitting the latent image insuch film to be fully developed;

. and a conveyor mechanism communicating with said film transportingmeans and said outlet opening of said heating chamber having a flatsupport thereunder conveying such developed-film to a collengths of filmin'substantially a horizontal manner.' I

and moved onto said roller'conveyor means before ,a. a heating chamber'havinginlet and outlet openings ner.

'12. The structure set forth in claim 10 wherein said heating chambermaintains a temperature range between 285 and 290 degrees Fahrenheit andsaid film transporting means moves such selected lengths ofmicrofilmthrough said heating chamber in substantially 5. 7 seconds.

1. An improvement in a duplicating mechanism for heat sensitive latentimage bearing microfilm having a film holder for holding such microfilmto be duplicated with a film exposure device disposed in operableposition in spaced and confronting relationship therewith, said filmexposure device cooperating with means for supplying film to be exposedto the film exposure device and having a cutter operably disposed andcontrolled to deliver selected lengths of exposed microfilm from saidfilm exposure device, said improvement comprising: a. a heating chamberhaving inlet and outlet openings formed therein admitting anddischarging said selected lengths of microfilm, said chamber including aplurality of heating elements disposed generally opposite the emulsionsurface of such selected lengths of exposed microfilm; b. filmtransporting means constructed and arranged within said heating chamberbetween said inlet and outlet openings and having continuously movingand changing contact areas engaging a substantially emulsionless surfaceof such selected lengths of microfilm, said transport means operating ata speed permitting the latent image in such film to be fully developed;c. and a conveyor mechanism communicating with said film transportingmeans and said outlet opening of said heating chamber having a flatsupport thereunder conveying such developed film to a collection point,said conveyor mechanism conveying such film in a flat condition untilthe film emulsion is set and the latent image is fixed therein.
 2. Thestructure set forth in claim 1 wherein said heating chamber includes:thermostatic control means connected to less than the total of saidplurality of heating elements providing incremental changes in heatvariations within said heating chamber.
 3. The structure set forth inclaim 1 wherein said inlet and outlet openings in said heating chamberare substantially in horizontal opposition to each other.
 4. Thestructure set forth in claim 1 wherein said film transporting meansincludes roller conveyor means constructed and arranged to convey suchselected lengths of film in substantially a horizontal manner.
 5. Thestructure set forth in claim 4 wheRein said conveyor mechanism includesan endless belt conveyor having at least a pair of rollers at each endthereof, the end communicating with said film transporting means havinga roller no larger in diameter than the rollers in said roller conveyormeans.
 6. The structure set forth in claim 1 wherein said heatingchamber maintains a temperature range between 285* and 290* Fahrenheit.7. The structure set forth in claim 6 wherein said film transportingmeans moves such selected lengths of microfilm through said heatingchamber in substantially 5 - 7 seconds.
 8. The structure set forth inclaim 2 wherein said heating chamber includes: a cavity containing saidplurality of heating elements, said cavity being disposed beneath saidfilm transporting means.
 9. The structure set forth in claim 4 whereinsaid film transporting means includes: a pair of rollers including apinch roller disposed adjacent said inlet opening between which suchselected lengths of exposed microfilm are engaged and moved onto saidroller conveyor means before being exposed to the heat from said heatingchamber.
 10. An improvement in a developer of heat sensitive imagebearing microfilm comprising: a. a heating chamber having inlet andoutlet openings formed therein admitting and discharging respectivelyselected lengths of exposed and developed microfilm, said chamberincluding a plurality of heating elements disposed generally oppositethe emulsion surface of such selected lengths of exposed microfilm; b.film transporting means constructed and arranged within said heatingchamber between said inlet and outlet openings and having continuouslymoving and changing contact areas engaging a substantially emulsionlesssurface of such selected lengths of microfilm, said transporting meansoperating at a speed permitting the latent image in such film to befully developed; c. and a conveyor mechanism communicating with saidfilm transporting means and said outlet opening of said heating chamberhaving a flat support thereunder conveying such developed film to acollection point, said conveyor mechanism conveying such film in a flatcondition until the film emulsion is set and the latent image is fixedtherein.
 11. The structure set forth in claim 10 wherein said inlet andoutlet openings in said heating chamber are substantially in horizontalopposition to each other and said film transporting means includesroller conveyor means constructed and arranged to convey such selectedlengths of film in substantially a horizontal manner.
 12. The structureset forth in claim 10 wherein said heating chamber maintains atemperature range between 285 and 290 degrees Fahrenheit and said filmtransporting means moves such selected lengths of microfilm through saidheating chamber in substantially 5 - 7 seconds.